TL;DR version: The Ubuntu Server people are clueless. Choose another platform for your servers.
At my current client, we recently discovered that a live server has since it was installed been silently dropping all output from cron on the floor. This turns out to be because of the base system of Ubuntu Server (in this case, version 8.04LTS) not including any mail capability, not even that of delivering to local files. Which, of course, means that cron has no way of delivering its reports. I reported this as a bug to the Ubuntu project, and got the bug closed with "Won't Fix". Their argument is that their policy is to have no listening ports open in the base system. While this is an excellent policy, it has absolutely nothing to do with the problem at hand, and their using that as an argument against local mail delivery (or, indeed, remote delivery) betrays such a severe lack of understanding that it casts doubt on the entire Ubuntu Server project.
At my current client, we recently discovered that a live server has since it was installed been silently dropping all output from cron on the floor. This turns out to be because of the base system of Ubuntu Server (in this case, version 8.04LTS) not including any mail capability, not even that of delivering to local files. Which, of course, means that cron has no way of delivering its reports. I reported this as a bug to the Ubuntu project, and got the bug closed with "Won't Fix". Their argument is that their policy is to have no listening ports open in the base system. While this is an excellent policy, it has absolutely nothing to do with the problem at hand, and their using that as an argument against local mail delivery (or, indeed, remote delivery) betrays such a severe lack of understanding that it casts doubt on the entire Ubuntu Server project.